Mother keeps telling me not to waste money because money is difficult nowadays.A. earnedB

问题补充：

Mother keeps telling me not to waste money because money is difficult nowadays.

A. earned

B. earning

C. to earn

D. to be earned

答案：

A. earned

B. earning

(答案→)C. to earn

D. to be earned

解析：句意：妈妈一直告诉我不要浪费钱，因为现在钱不好挣。这里使用了句型“Sth+be+adj+to do”，这个句型中不定式用主动表示被动，所以选C。